The Effect of a 30-Min Water-Pipe Smoking Session on Cognitive Measures and Cardio-Pulmonary Parameters

Introduction: One session of water-pipe tobacco smoking (WPS) can increase carboxyhemoglobin (COHb) to levels comparable to those reported in carbon monoxide poisoning, which may cause memory impairment and confusion.

Methods: A prospective study evaluating healthy volunteers pre- and post-30 min of WPS session. Primary outcome parameters were executive cognitive measures [digit span test and Paced Auditory Serial Addition Test (PASAT)]. The effect of repeated cognitive testing 30 min apart without WPS was evaluated in age- and sex-matched healthy volunteers. Secondary outcome parameters included cardio-pulmonary, COHb, serum nicotine, and cytokine changes.

Results: Thirty-five subjects aged 25.6 ± 4.5 years smoked water-pipe for a 30-min session. Control group included 20 subjects aged 25.2 ± 5.1 years. Digit span test median score decreased after WPS (16 and 15, respectively, p = .003), insignificant decrease in controls. Median PASAT score increased after WPS (49 and 52, respectively, p = .009); however, a much larger significant increase was observed in controls (p ≤ .001). One WPS session resulted in significant increases in heart and respiratory rates and significant decrease in FEF25-75%. Post WPS, median COHb levels increased (from 2.2% to 10.7%, p < .0001) as did median serum nicotine levels (from 1.2 to 26.8 ng/mL, p < .0001). Serum cytokines levels: IL-2 and IL-6 increased (p < .0001 for each), and IL-10 and IL-5 decreased (p < .0001 and p = .04, respectively).

Conclusions: One session of WPS resulted in significant negative effects on cognitive executive measures, significant increases in COHb and serum nicotine levels, and significant changes in serum cytokines. Our findings call for increasing awareness towards the possible consequences of cognitive alterations following a 30-min session of WPS.

Implications: One 30-min session of water-pipe smoking resulted in negative effects on executive cognitive measures, increased carboxyhemoglobin and serum nicotine, and significant changes in serum cytokine levels. This study adds to the accumulating evidence on the harmful effects of water-pipe smoking, a growing epidemic, and calls for awareness of its possible consequences of acute cognitive alterations.